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  • Astrophysics  (2,598)
  • Spacecraft Propulsion and Power
  • ddc:330
  • 2020-2022  (32)
  • 2015-2019  (1,908)
  • 2000-2004  (2,663)
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  • 1
    Publication Date: 2021-08-06
    Description: Energy poverty is high up on national and European Union policy agendas. A number of possible indicators to measure the issue have been identified in the literature, but comparable data with European coverage is scarce. The EU Commission thus proposes four independent indicators on the "EU Energy Poverty Observatory" based on self-reported items from the pan-European surveys on income and living conditions (SILC) and household budgets (HBS). It is of increasing public interest to analyse social impacts of energy policies, and quantify energy poverty indicators also from modelling. This paper first shortly outlines how the expenditure-based indicators using HBS micro data may be directly linked to existing macroeconomic models through their defining variables (energy expenditure and income). As endogenous modelling based on micro data is difficult, the link may be country-specific elasticities. The main contribution of the paper is a systematic in-depth sensitivity analysis of the two indicators to changes in income and energy expenditure following varying patterns in the underlying distributions of the micro data. The results may be used by future soft links to models. The results display sometimes counterintuitive effects. We find that whether these indicators increase/decrease after a change of income or energy expenditure largely depends on the specific country-wise income and energy expenditure distribution between households on a micro-level. Due to their definition, the examined indicators are especially sensitive, when income changes alter the indicator threshold values, which in these cases are the median values in underlying distributions. We discuss these findings and relate them to several indicator shortcomings and potential remedies through changes in indicator definition.
    Keywords: ddc:330
    Repository Name: Wuppertal Institut für Klima, Umwelt, Energie
    Language: English
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  • 2
    Publication Date: 2021-08-06
    Description: In order to calculate the financial return of energy efficiency measures, a cost-benefit analysis (CBA) is a proven tool for investors. Generally, however, most CBAs for investors have a narrow focus, which is - simply speaking - on investment costs compared with energy cost savings over the life span of the investment. This only provides part of the full picture. Ideally, a comprehensive or extended CBA would take additional benefits as well as additional costs into account. The objective of this paper is to reflect upon integrating into a CBA two important cost components: transaction costs and energy efficiency services - and how they interact. Even though this concept has not been carried out to the knowledge of the authors, we even go a step further to try to apply this idea. In so doing, we carried out a meta-analysis on relevant literature and existing data and interviewed a limited number of energy experts with comprehensive experience in carrying out energy services. Even though data is hardly available, we succeeded in constructing three real-world cases and applied an extended CBA making use of information gathered on transaction costs and energy services costs. We were able to show that, despite these additional cost components, the energy efficiency measures are economically viable. Quantitative data was not available on how energy services reduce transaction costs; more information on this aspect could render our results even more positive. Even though empirical and conceptual research must intensify efforts to design an even more comprehensive CBA, these first-of-its-kind findings can counterargue those that believe energy efficiency is not worth it (in monetary terms) due to transaction costs or energy services costs. In fact, this is good news for energy efficiency and for those that seek to make use of our findings to argue in favor of taking up energy efficiency investments in businesses.
    Keywords: ddc:330
    Repository Name: Wuppertal Institut für Klima, Umwelt, Energie
    Language: English
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  • 3
    Publication Date: 2021-05-04
    Keywords: ddc:330
    Repository Name: Wuppertal Institut für Klima, Umwelt, Energie
    Language: German
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  • 4
    Publication Date: 2021-07-05
    Description: This chapter turns to the measurement of performance in delivering corporate and ecosystem purposes. The metrics are designed to capture the pain points in the ecosystem that need to be addressed and the success of the intervention in addressing them. This requires measures of non-financial as well as financial performance. The chapter provides an overview of measurements of non-financial forms of capital: natural, human, and social. In examining natural capital, it contrasts input measures that record the amount of natural resources that are used in the production process and output measures that examine the impact of the inputs on products, emissions, waste, etc. It notes that measuring inputs is in general more straightforward than outputs and it therefore argues that natural capital metrics should be constructed around inputs rather than outputs.
    Keywords: ddc:330
    Repository Name: Wuppertal Institut für Klima, Umwelt, Energie
    Language: English
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  • 5
    Publication Date: 2021-05-21
    Keywords: ddc:330
    Repository Name: Wuppertal Institut für Klima, Umwelt, Energie
    Language: German
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  • 6
    Publication Date: 2021-05-18
    Description: Unser Papier entwickelt Maßnahmen für eine "Just transition"-Governance als Grundlage einer Politischen Ökonomie im Strukturwandel. Für eine Fallstudie im Rheinischen Braunkohlerevier wurden sechs Experteninterviews mit Bürgerinitiativen, Gewerkschaften und Vertretern des Landes Nordrhein-Westfalen durchgeführt. Die Ergebnisse zeigen den Bedarf an politischen Maßnahmen in verschiedenen Bereichen auf: Während für die Traditionsfirmen der Braunkohleindustrie und deren Beschäftigten eine Vielzahl von Förderpolitiken entwickelt wurde und wird, erhalten Beschäftigte von Subunternehmen kaum Unterstützung im Strukturwandel. Letztere sind daher einem hohen Risiko ausgesetzt, durch den Ausstieg aus der Kohleförderung ihren Arbeitsplatz zu verlieren. Die Interviews zeigten auch, dass im Rheinischen Braunkohlerevier aufgrund des geltenden Bergbaugesetzes Flächen zu einer knappen Ressource werden könnten. Der Akteurszentrierte Institutionalismus wird genutzt, um Maßnahmen abzuleiten, die den Bedürfnissen der verschiedenen Interessengruppen entsprechen. Abschließend werden Bezüge sowohl zum Transition Management als auch zur Politischen Ökonomie hergestellt.
    Keywords: ddc:330
    Repository Name: Wuppertal Institut für Klima, Umwelt, Energie
    Language: German
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  • 7
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    München : Oekom
    Publication Date: 2021-05-04
    Keywords: ddc:330
    Repository Name: Wuppertal Institut für Klima, Umwelt, Energie
    Language: German
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  • 8
    Publication Date: 2021-07-05
    Description: The data centre industry (DCI) has grown from zero in the 1980s, to enabling 60% of the global population to be connected in 2021 via 7.2 million data centres. The DCI is based on a linear economy and there is an urgent need to transform to a Circular Economy to establish a secure supply chain and ensure an economically stable and uninterrupted service, which is particularly difficult in an industry that is comprised of ten insular subsectors. This paper describes the CEDaCI project which was established to address the challenge in this unique sector; this ground-breaking project employs a whole systems approach, Design Thinking and the Double Diamond methods, which rely on people/stakeholder engagement throughout. The paper reviews and assesses the impact of these methods and project to date, using quantitative and qualitative research, via an online sectoral survey and interviews with nine data centre and IT industry experts. The results show that the project is creating positive impact and initiating change across the sector and that the innovative output (designs, business models, and a digital tool) will ensure that sectoral transformation continues; the project methods and structure will also serve as an exemplar for other sectors.
    Keywords: ddc:330
    Repository Name: Wuppertal Institut für Klima, Umwelt, Energie
    Language: English
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  • 9
    Publication Date: 2021-09-08
    Keywords: ddc:330
    Repository Name: Wuppertal Institut für Klima, Umwelt, Energie
    Language: German
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  • 10
    Publication Date: 2021-12-03
    Description: The rising popularity and strong increase in the number of electric bicycles make it necessary to consider the built-in resources as well as possible treatments after the use phase. The time lag between the purchase and the occurrence of relevant defects suggests significant increases in defective components. Especially the great dynamics of the market due to regular innovations, product renewals, and the lack of spare parts availability for older models make the long-term use by customers much more difficult than for conventional bicycles. Therefore, it is necessary to analyze circular business models for the electric bicycle market. In this way, the required structures for a sustainable electric bicycle industry can be created so that valuable materials do not go into disposal but undergo a new use phase. Based on the results of "AddRE-Mo-Value Preservation Scenarios for Urban Electromobility of Persons and Loads through Additive Manufacturing and Remanufacturing," a research project funded by the German Federal Ministry of Education and Research, this paper addresses four circular business models, two sales models, and two service models. The guiding research interest of this paper is the combination of remanufacturing and additive manufacturing from a business model perspective, analyzing the extent to which additive remanufacturing can be considered a solution for electric bicycles' circularity. After describing the approach and methods used to develop these four circular business models the business models are described and analyzed using the Business Model Canvas. Based on this analysis, it is shown that the combination of remanufacturing and additive manufacturing can be applied to the electric bicycle market and be integrated into both sales and service models. The description of these business models will help managers design viable business models in the context of sustainable electric bicycles. It also shows that the individual partners within the value chain must collaborate more closely. In the electric bicycle industry, a single company will probably not be able to close the product cycle completely. Further research is needed to develop concepts of the business models and examine their practical feasibility in technical and organizational operations to achieve a circular economy.
    Keywords: ddc:330
    Repository Name: Wuppertal Institut für Klima, Umwelt, Energie
    Language: English
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  • 11
    Publication Date: 2021-11-11
    Keywords: ddc:330
    Repository Name: Wuppertal Institut für Klima, Umwelt, Energie
    Language: German
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  • 12
    Publication Date: 2021-11-11
    Keywords: ddc:330
    Repository Name: Wuppertal Institut für Klima, Umwelt, Energie
    Language: Russian
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  • 13
    Publication Date: 2021-11-11
    Description: Reuse is still seen as a "niche phenomenon" and consumers seem to waste economic opportunities linked to buying and selling second-hand products. For this reason, this paper focuses on incentives and barriers to sell and buy second-hand products, as indicated in the literature, and applies a theoretical framework of transaction costs to explain the existing consumption patterns. For this paper, a representative online survey was conducted in which 1023 consumers in Germany participated, age 16 and older. The data were analyzed for statistically significant deviations between different groups of economic actors selling or buying second-hand products. Results show that valuable unused products exist in households, but barriers such as uncertainties about the reliability of the buyer or the quality of the product hinder the transition into sustainable consumption. Different forms of transaction costs are important explanatory variables to explain why consumers nevertheless predominantly buy new products, although they are aware that second-hand would save money and make an individual contribution to climate protection.
    Keywords: ddc:330
    Repository Name: Wuppertal Institut für Klima, Umwelt, Energie
    Language: English
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  • 14
    Publication Date: 2021-11-11
    Description: This paper argues that, although Japan's and Germany's energy transition paths differ in detail, a trend towards decentralisation is clearly evident in both countries. Based on comprehensive screening, own stocktaking and the results of a stakeholder dialogue, this paper highlights the motivation for different local actors to enter the energy market in both countries. Although there are challenges to success in a market dominated by large energy companies, this paper argues that the benefits to local communities outweigh the efforts. Overall, it is shown that democratisation and the decentralisation of the energy system are suitable to facilitate a successful transformation process in both countries.
    Keywords: ddc:330
    Repository Name: Wuppertal Institut für Klima, Umwelt, Energie
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  • 15
    Publication Date: 2021-11-26
    Description: More and more companies are announcing their intention to become climate-neutral and numerous companies already offer climate-neutral products or services: From climate-neutral parcel delivery to air travel. But what exactly do the companies' net-zero targets mean? Is the target set ambitious? And what role does offsetting play, i.e., purchasing carbon credits that are accounted against the company's own climate target? The approaches behind the proclaimed targets are often difficult to understand. Against this background, this Zukunftsimpuls provides ten recommendations for the definition and implementation of neutrality targets. Among other things, the authors advocate the use of a robust database as the basis for net-zero targets, emphasize the importance of transparent communication, and highlight the role that offsetting should play. Purchased carbon credits should make as limited a contribution as possible for meeting climate targets and should only be used to offset emissions that cannot be reduced or avoided. More generally, net-zero targets should not be made the sole criterion for ambitious climate strategies. Rather, they are a building block of a much more comprehensive strategy of corporate climate action.
    Keywords: ddc:330
    Repository Name: Wuppertal Institut für Klima, Umwelt, Energie
    Language: English
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  • 16
    Publication Date: 2021-02-10
    Description: Als Herausforderung der Verkehrswende werden häufig die möglicherweise wegfallenden Arbeitsplätze diskutiert. Denn die Beschäftigung der Automobilindustrie in Deutschland gilt als wichtiges Argument für einen sozialverträglichen Strukturwandel. Aber auch die Wirtschaftszweige des Umweltverbunds bieten viele Arbeitsplätze. Vor diesem Hintergrund untersucht die vorliegende Studie des Wuppertal Instituts und des Instituts Arbeit und Technik der Westfälischen Hochschule die Beschäftigtenzahlen in Teilmärkten der Fahrradwirtschaft sowie deren Umsatzentwicklung.
    Keywords: ddc:330
    Repository Name: Wuppertal Institut für Klima, Umwelt, Energie
    Language: German
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  • 17
    Publication Date: 2021-05-04
    Keywords: ddc:330
    Repository Name: Wuppertal Institut für Klima, Umwelt, Energie
    Language: German
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  • 18
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    Wuppertal : Wuppertal Institut für Klima, Umwelt, Energie
    Publication Date: 2021-05-18
    Description: The European Union (EU) has established that the goal of achieving climate neutrality by 2050 as a key driver of innovation and growth for industry and the economy in the EU. In addition to offering great opportunities, this also poses considerable challenges for the European economy and, for the most part, for basic industries, which are particularly emission-intensive and face strong international competition. An integrated climate and industry strategy is of central importance to protecting the climate, since the production of steel, cement, basic chemicals, glass, paper, and other materials in the EU and worldwide accounts for roughly one fifth of total greenhouse gas emissions. Even in a greenhouse gas-neutral future, we will not be able to fully eliminate our need for these materials. At the same time, it is particularly challenging to produce these materials without creating emissions given the state of technology and the necessary infrastructures. This applies above all to the question of how large amounts of green energy, including electricity and hydrogen, can be produced at competitive prices. Analyses show that despite the considerable costs involved in process changeover, the costs of transforming the raw materials industry are acceptable to society as a whole, given that the additional costs usually only increase the price of the end products by a few percentage points. However, in the case of crude steel or cement, the price would increase by between one third and 100 per cent. Since almost all raw materials manufacturers face strong global market competition, in most cases they are not able to bankroll the investments in climate-neutral production and the required energy infrastructure without outside support. This paper outlines an integrated climate industrial policy package that allows the EU to utilise its existing technological leadership in many of these industries to build a greenhouse gas-neutral raw materials industry.
    Keywords: ddc:330
    Repository Name: Wuppertal Institut für Klima, Umwelt, Energie
    Language: English
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  • 19
    Publication Date: 2021-05-06
    Description: In the light of Germany's chosen path towards the energy transition, the regulatory framework has changed considerably. New players have succeeded in entering the market, and renewable energies have become increasingly competitive. Greater electrification of the transport and heating sectors will be needed in the future to achieve national climate targets. Against this background, Germany's big energy companies need to be sure that their sales will increase. However, they were unable to anticipate this development, and made strategic mistakes in the past. The development of sustainable business models in line with the energy transition failed to materialize. Now it is becoming increasingly clear that companies must create new business models to survive in the long term. These business models have to keep with the tradition, whilst meeting the needs of low-carbon power supplies. In this paper, we will examine the past and future challenges of the four energy companies and develop a proposal for evaluating sustainable business models. For this purpose, we use the multi-level perspective to categorize developments in the electricity market over the last 50 years, and then apply a multi-criteria analysis to derive five suitable business models from the results.
    Keywords: ddc:330
    Repository Name: Wuppertal Institut für Klima, Umwelt, Energie
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  • 20
    Publication Date: 2021-05-04
    Keywords: ddc:330
    Repository Name: Wuppertal Institut für Klima, Umwelt, Energie
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  • 21
    Publication Date: 2021-05-04
    Keywords: ddc:330
    Repository Name: Wuppertal Institut für Klima, Umwelt, Energie
    Language: German
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  • 22
    Publication Date: 2020-10-28
    Keywords: ddc:330
    Repository Name: Wuppertal Institut für Klima, Umwelt, Energie
    Language: German
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  • 23
    Publication Date: 2021-05-04
    Keywords: ddc:330
    Repository Name: Wuppertal Institut für Klima, Umwelt, Energie
    Language: German
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  • 24
    Publication Date: 2021-05-18
    Description: In this paper, we aim to present a comprehensive analysis on the emerging phenomenon of distributed innovation in commons-based peer production (CBPP) platforms. Starting with the exploration of the widely held belief on value-creation confined to industrial settings, we raise several questions regarding the feasibility of, and a need for, an inclusive innovation process that can tap grassroots capacity into both traditional (industrial research and development) and emerging (peer-to-peer) innovation models to yield sustainable solutions. In particular, we explore the emergence and structuration of digital innovations in the maker movement, as it presents an alternative construct of innovation wherein access to and sharing of knowledge is predominantly distributed. With innovation outcomes often freely revealed, its very structuration could pose a principal challenge to our conceptualizations of value creation and competitive advantage in the current economic model. Drawing from responses received from 200 collaborative innovation platforms, six semi‐structured interviews focusing on socio-technical innovation cases, as well as four in-depth narrative interviews with maker turned entrepreneurs, we present a detailed analysis on the topology of network, typology of actors, as well as the underlying innovation ecosystem in CBPP networks in Germany. In doing so, we contribute to the conceptualization of peer-to-peer distributed innovations in collaborative platforms.
    Keywords: ddc:330
    Repository Name: Wuppertal Institut für Klima, Umwelt, Energie
    Language: English
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  • 25
    Publication Date: 2021-05-04
    Keywords: ddc:330
    Repository Name: Wuppertal Institut für Klima, Umwelt, Energie
    Language: German
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  • 26
    Publication Date: 2021-05-04
    Keywords: ddc:330
    Repository Name: Wuppertal Institut für Klima, Umwelt, Energie
    Language: German
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  • 27
    Publication Date: 2020-01-22
    Description: TESS launched 18 April 2018 to conduct a two-year, near all-sky survey for at least 50 small, nearby exoplanets for which masses can be ascertained and whose atmospheres can be characterized by ground- and space-based follow-on observations. TESS has completed its survey of the southern hemisphere and begun its survey of the northern hemisphere, identifying 〉1000 candidate exoplanets and unveiling a plethora of exciting non-exoplanet astrophysics results, such as asteroseismology, asteroids, and supernova. The TESS Science Processing Operations Center (SPOC) processes the data downlinked every two weeks to generate a range of data products hosted at the Mikulski Archive for Space Telescopes (MAST). For each sector (~1 month) of observations, the SPOC calibrates the image data for both 30-min Full Frame Images (FFIs) and up to 20,000 pre-selected 2-min target star postage stamps. Data products for the 2-min targets include simple aperture photometry and systematic error-corrected flux time series. The SPOC also conducts searches for transiting exoplanets in the 2-min data for each sector and generates Data Validation time series and associated reports for each transit-like feature identified in the search. Multi-sector searches for exoplanets are conducted periodically to discover longer period planets, including those in the James Webb Continuous Viewing Zone (CVZ), which are observed for up to one year. Starting with Sector 8, scattered light from the Earth and Moon contaminated significant portions of the data in each orbit. We have developed algorithms for automated identification of the scattered light features at the individual target level. Previously, data for all stars on a CCD affected by scattered light were manually excluded. The automated flagging will allow us to retain significantly more data for stars that are not affected by the scattered light even though it is occurring elsewhere on the CCD. We also discuss enhancements to the SPOC pipeline and the newly available FFI light curves. The TESS Mission is funded by NASA's Science Mission Directorate as an Astrophysics Explorer Mission.
    Keywords: Astrophysics
    Type: ARC-E-DAA-TN76812 , American Astronomical Society Meeting; Jan 04, 2020 - Jan 08, 2020; Honolulu, HI; United States
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  • 28
    Publication Date: 2020-01-21
    Description: Habitable Exoplanet Observatory Mission (HabEx) will image & spectroscopically characterize planetary systems in the habitable zone around nearby sun-like stars. Additionally, HabEx will perform a broad range of general astrophysics science enabled by a 150 to 1700 nm spectral range and 3 x 3 arc-minute FOV. Critical to achieving the HabEx science goals is a large, ultra-stable telescope. The baseline HabEx telescope is a 4-m off-axis unobscured three-mirror-anastigmatic design with diffraction limited performance at 400 nm and wavefront stability of picometers per mK. These specifications are driven by science requirements. STOP (structural thermal optical performance) analysis predicts that the baseline telescopes opto-mechanical design meets its specified performance tolerances.
    Keywords: Astrophysics
    Type: MSFC-E-DAA-TN75627 , American Astronomical Society Meeting; Jan 04, 2020 - Jan 08, 2020; Honolulu, HI; United States
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  • 29
    Publication Date: 2020-01-18
    Description: After successful validation of the design, swaged cathode heaters have been delivered by the NASA Glenn Research Center to Aerojet Rocketdyne for the fabrication of the NEXT-C ion thruster . NASA Glenn Research Center re-established and validated process controls as well as completed cyclic life testing of development heaters. Following an extensive requalification program, fabrication of a flight batch of heaters was executed using the qualified process controls. Of the 28 heaters fabricated in this flight batch, a set of six heaters were acceptance and cyclic tested to verify conformance with operational requirements. Upon completion of 200 percent of the NEXT-C cyclic requirement, the heater batch was certified by NASA for use in the flight hollow cathodes. Nine heaters from the batch of 28 were provided to Aerojet Rocketdyne in early 2018 for cathode fabrication. This paper summarizes the acceptance and cyclic life testing of the flight heaters and preliminary findings of post-test analyses.
    Keywords: Spacecraft Propulsion and Power
    Type: NASA/TM-2020-219454 , E-19773 , AIAA Paper–2019–4167 , GRC-E-DAA-TN72218 , Propulsion and Energy Forum and Exposition; Aug 19, 2019 - Aug 22, 2019; Indianapolis, IN; United States
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  • 30
    Publication Date: 2020-01-15
    Description: No abstract available
    Keywords: Astrophysics
    Type: MSFC-E-DAA-TN76756 , American Astronomical Society Meeting; Jan 04, 2020 - Jan 08, 2020; Honolulu, HI; United States
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  • 31
    Publication Date: 2020-01-18
    Description: NASA is continuing the development of a 12.5-kW Hall thruster system to support a phased exploration concept to expand human presence to cis-lunar space and eventually to Mars. The development team is transitioning knowledge gained from the testing of the government-built Technology Development Unit (TDU) to the contractor-built Engineering Test Unit (ETU). A new laser-induced fluorescence diagnostic was developed to obtain data for validating the Hall thruster models and for comparing the behavior of the ETU and TDU. Analysis of TDU LIF data obtained during initial deployment of the diagnostics revealed evidence of two streams of ions moving in opposite directions near the inner front pole. These two streams of ions were found to intersect the downstream surface of the front pole at large oblique angles. This data points to a possible explanation for why the erosion rate of polished pole covers were observed to decrease over the course of several hundred hours of thruster operation.
    Keywords: Spacecraft Propulsion and Power
    Type: NASA/TM-2020-220452 , GRC-E-DAA-TN72248
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  • 32
    Publication Date: 2020-01-16
    Description: No abstract available
    Keywords: Astrophysics
    Type: MSFC-E-DAA-TN76707 , American Astronomical Society Meeting; Jan 04, 2020 - Jan 08, 2020; Honolulu, HI; United States
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  • 33
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    Wuppertal : Wuppertal Institut für Klima, Umwelt, Energie
    Publication Date: 2021-08-06
    Description: Mit fortschreitender Energiewende steigt der Anteil erneuerbarer Energien im Strommix. Deren Angebot variiert im Tagesverlauf, nach Wetterlage und saisonal. Um Angebot und Nachfrage zur Deckung zu bringen, benötigt es daher Speicher mit großen Kapazitäten. Von allen technologischen Optionen mit großer Speicherkapazität sind Wasser-Pumpspeicherwerke die einzige, die langjährig erprobt und wirtschaftlich ist. Diese könnten in Braunkohletagebauen, welche im Zuge der Energiewende aufgegeben werden, errichtet werden. Unsere Überschlagsrechnung am Beispiel eines Pumpspeicherwerks in den heutigen Tagebauen Hambach, Garzweiler und Inden zeigt, dass diese mit bis zu 400 GWh ein signifikantes technisches Speicherpotenzial haben. Dies entspricht etwa der kontinuierlichen Maximalleistung eines Kernkraftwerks über zwei Wochen. Im Kontext der Diskussion um den Braunkohleausstieg skizziert das Papier ein netzdienliches Nachnutzungskonzept für Braunkohletagebaue, das zumindest für einen Teil der heute in der Kohleförderung und -Verstromung Beschäftigten mögliche Zukunftsperspektiven bietet.
    Keywords: ddc:330
    Repository Name: Wuppertal Institut für Klima, Umwelt, Energie
    Language: German
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  • 34
    Publication Date: 2019-08-07
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  • 35
    Publication Date: 2019-08-07
    Keywords: ddc:330
    Repository Name: Wuppertal Institut für Klima, Umwelt, Energie
    Language: German
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  • 36
    Publication Date: 2021-05-04
    Keywords: ddc:330
    Repository Name: Wuppertal Institut für Klima, Umwelt, Energie
    Language: German
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  • 37
    Publication Date: 2019-12-16
    Description: Die Dekarbonisierung des deutschen Wohngebäudebestandes stellt einen wichtigen Baustein zum Gelingen der Energiewende dar. Politisches Ziel ist ein "nahezu klima-neutraler" Gebäudebestand bis 2050. Trotz Erfolgen in der Vergangenheit und eines umfangreichen Policy-Mix verbleibt die energetische Sanierungstätigkeit sowohl hinichtlich der Sanierungstiefe als auch der Sanierungsbreite unterhalb des politisch geforderten und ökologisch notwendigen Maßes. Die Arbeit widmet sich daher der Frage, unter welchen individuellen und quartiersbezogenen Rahmenbedingungen Immobilieneigentümer energetische Sanierungsmaßnahmen durchführen und wie die energetische Sanierungstätigkeit durch Multi-Level-Governance gesteigert werden kann. Die Analyse erfolgt fallstudienbasiert für die Eigentümergruppe der privaten Kleinvermieter, die rund 37 Prozent des deutschen Wohnungsbestandes bewirtschaften. Anhand eines mixed method-Ansatzes wird zunächst durch problemzentrierte Interviews ein Modell zur Beschreibung des Investitionsentscheidungsprozesses entwickelt, was anschließend durch eine schriftlich-postalische Befragung und ihre regressions-analytische Auswertung bewertet wird. Durch die Triangulation können förderliche und hemmende Einflussfaktoren identifiziert werden. Aufbauend auf den theoretischen Vorüberlegungen sowie den empirischen Ergebnissen werden anschließend politische Handlungsempfehlungen abgeleitet.
    Keywords: ddc:330
    Repository Name: Wuppertal Institut für Klima, Umwelt, Energie
    Language: German
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  • 38
    Publication Date: 2021-05-04
    Keywords: ddc:330
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  • 39
    Publication Date: 2021-05-04
    Keywords: ddc:330
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  • 40
    Publication Date: 2021-05-04
    Keywords: ddc:330
    Repository Name: Wuppertal Institut für Klima, Umwelt, Energie
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  • 41
    Publication Date: 2019-08-07
    Keywords: ddc:330
    Repository Name: Wuppertal Institut für Klima, Umwelt, Energie
    Language: German
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  • 42
    Publication Date: 2022-02-18
    Description: Zwischen 2005 und 2016 gab es in Deutschland über 150 Stadtwerke-Neugründungen im Energiebereich. Die insgesamt rund 900 Stadtwerke, die heute im Energiesektor tätig sind, spielen für die Energiewende eine zentrale Rolle. Denn sie stellen weit über die Hälfte der Versorgung an Strom, Gas und Wärme sicher. Zudem haben Stadtwerke aufgrund ihrer kommunalen Verankerung eine besondere Position im Spannungsgefüge von Politik, Wirtschaft und Zivilgesellschaft. Dieser Beitrag zeigt auf, welche Gründe und Motive zu dieser Gründungswelle führten und welche Erfolgsfaktoren für Stadtwerke-Neugründungen ausschlaggebend waren.
    Keywords: ddc:330
    Repository Name: Wuppertal Institut für Klima, Umwelt, Energie
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  • 43
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    Jakarta : Economic Research Institute for ASEAN and East Asia (ERIA)
    Publication Date: 2022-02-18
    Keywords: ddc:330
    Repository Name: Wuppertal Institut für Klima, Umwelt, Energie
    Language: English
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  • 44
    Publication Date: 2022-02-18
    Description: Ein CO2-Preis ist ein zentrales Instrument, um eine umfassende Dekarbonisierung der Wirtschaft zu ermöglichen und zu erleichtern. Sie kann durch verschiedene Instrumente umgesetzt werden, insbesondere in Form einer CO2-Steuer. Es ist jedoch wichtig, dass ein CO2-Preis allein - aufgrund der vielfältigen Hindernisse (einschließlich nicht ökonomischer Hemmnisse) - die sektoralen Ziele und Instrumente nicht ersetzen kann. Vielmehr muss er komplementär zu sektorspezifischen Klimaschutzinstrumenten eingeführt werden. Der Artikel gibt Auskunft darüber, wie ein CO2-Preis konkret und angemessen ausgestaltet werden kann.
    Keywords: ddc:330
    Repository Name: Wuppertal Institut für Klima, Umwelt, Energie
    Language: German
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  • 45
    Publication Date: 2022-02-18
    Description: Elektro- und Elektronikaltgeräte enthalten eine Vielzahl von umwelt- und ressourcenrelevanten Metallen wie Gold und Neodym, welche derzeit noch nicht optimal recycelt werden. Im vorliegenden Projekt wurden die Mengenpotenziale von 10 dieser Metalle in 30 ressourcenrelevanten Elektrogerätearten quantifiziert und die bestehenden Verluste bei der Elektroaltgeräte-Entsorgung von der Sammlung über die Behandlung bis zur Metallrückgewinnung über Mengenstrombilanzen ermittelt, teilweise unterstützt durch Sortieranalysen und Behandlungsversuche. Die Studie leitet daraus Maßnahmenempfehlungen zur Optimierung der Erfassungsstrukturen sowie der Behandlungs- und Verwertungssysteme für Elektroaltgeräte aus privaten Haushalten zur Rückgewinnung der betrachteten Metalle ab.
    Keywords: ddc:330
    Repository Name: Wuppertal Institut für Klima, Umwelt, Energie
    Language: German
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  • 46
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    Jakarta : Economic Research Institute for ASEAN and East Asia (ERIA)
    Publication Date: 2022-02-18
    Keywords: ddc:330
    Repository Name: Wuppertal Institut für Klima, Umwelt, Energie
    Language: English
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  • 47
    Publication Date: 2022-02-18
    Description: Ex-ante policy evaluation requires a detailed understanding of how the subjects addressed by the policy react to its implementation. In the context of energy efficiency, policy measures typically aim at influencing investment decisions towards more efficient options. As has been discussed widely in the context of the "energy efficiency gap", investments in energy efficiency improvements are frequently not conducted even though they seem cost-effective from a simple cost-benefit perspective, where transaction costs have been identified as one important barrier. While transaction costs have been discussed widely from a conceptional perspective, empirical studies quantifying transaction costs and measures to reduce them are rare. This paper presents approaches, results and insights from a recently completed research project funded by the German Federal Energy Efficiency Center (BfEE), addressing transaction costs in various energy efficiency measures and the role of energy efficiency services to overcome the barrier. We analyse a set of 11 energy efficiency investments covering private households, public institutions and the industry sector. We gather data on direct investment costs and energy cost savings and provide a detailed analysis of the various barriers and transaction costs associated with the implementation. We then analyse the costs of existing energy efficiency services using data provided by the BfEE. We compare the different cost elements and analyze the potential of energy efficiency services to reduce transaction costs. We find that the role of transaction costs differs substantially between households, public institutions and companies and that the impact of energy efficiency services on transaction costs needs to be evaluated using different methodological approaches. We conclude that while data availability on disaggregated transaction costs is a major challenge, energy services can reduce transaction costs considerably.
    Keywords: ddc:330
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  • 48
    Publication Date: 2022-02-18
    Description: Because prevention is closely linked to complex consumption patterns, even cultural changes, such as increasing environmental awareness, changes in the average size of households or changes in the industrial structure of an economy, are relevant factors for the interpretation of changes in the generation of waste - it is more or less impossible to isolate the effect of specific waste prevention measures in this complex system. This must be considered, in particular, in international comparisons of policies and their potential transferability. The guidelines of the European Commission on waste prevention also point to the particular problem of data availability in the area of prevention: as waste statistics focus mainly on the treatment and fate of wastes, they are often of limited value for prevention of waste because they don't give sufficient information about their origins or reasons for their generation. Against this background, this report has the following objectives: Chapter 2 discusses strengths and weaknesses of typical waste-based prevention indicators; Chapter 3 analyses possible indicators that consider an upstream perspective and take into account the ecological rucksacks of products and components that have become waste; Chapter 4 focuses on specific product groups that could be targeted by waste prevention indicators. In general, the report describes the complexity of measuring waste prevention and outlines pros and cons of possible approaches. The final chapter aims to draw rather pragmatic conclusions on possibly most preferable options for future policy-making.
    Keywords: ddc:330
    Repository Name: Wuppertal Institut für Klima, Umwelt, Energie
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  • 49
    Publication Date: 2022-01-20
    Keywords: ddc:330
    Repository Name: Wuppertal Institut für Klima, Umwelt, Energie
    Language: German
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  • 50
    facet.materialart.
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    Wuppertal : Wuppertal Institut für Klima, Umwelt, Energie
    Publication Date: 2022-11-10
    Description: Mit fortschreitender Energiewende steigt der Anteil erneuerbarer Energien im Strommix. Deren Angebot variiert im Tagesverlauf, nach Wetterlage und saisonal. Um Angebot und Nachfrage zur Deckung zu bringen, benötigt es daher Speicher mit großen Kapazitäten. Von allen technologischen Optionen mit großer Speicherkapazität sind Wasser-Pumpspeicherwerke die einzige, die langjährig erprobt und wirtschaftlich ist. Diese könnten in Braunkohletagebauen, welche im Zuge der Energiewende aufgegeben werden, errichtet werden. Unsere Überschlagsrechnung am Beispiel eines Pumpspeicherwerks in den heutigen Tagebauen Hambach, Garzweiler und Inden zeigt, dass diese mit bis zu 400 GWh ein signifikantes technisches Speicherpotenzial haben. Dies entspricht etwa der kontinuierlichen Maximalleistung eines Kernkraftwerks über zwei Wochen. Im Kontext der Diskussion um den Braunkohleausstieg skizziert das Papier ein netzdienliches Nachnutzungskonzept für Braunkohletagebaue, das zumindest für einen Teil der heute in der Kohleförderung und -Verstromung Beschäftigten mögliche Zukunftsperspektiven bietet.
    Keywords: ddc:330
    Repository Name: Wuppertal Institut für Klima, Umwelt, Energie
    Language: German
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  • 51
    Publication Date: 2022-11-10
    Description: Die vorliegende Arbeit verfolgt die Zielsetzung, den Beitrag verschiedener politischer Handlungsoptionen zur Steigerung der betrieblichen Energieeffizienz zu ermitteln. Eingangs wird aufgezeigt, inwieweit die Steigerung der Energieeffizienz aufgrund ihrer vielfältigen Vorteile eine Einstufung als eigenständige Zielgröße rechtfertigt im Gegensatz zu einer bloßen Betrachtung als Mittel zum Zweck des Klimaschutzes. Für die anschließende quantitative Analyse wurden Daten aus dem Projekt Energieeffizienz Impulsgespräche des Rationalisierungs- und Innovationszentrums der Deutschen Wirtschaft (RKW) e.V. aus den Jahren 2011 bis 2013 mit eigens für diese Arbeit erhobenen Daten von 2017 für dieselben Unternehmen verglichen. Zu diesem Zweck wird ein difference-in-differences-Ansatz genutzt. Im Ergebnis erweisen sich Preise im Gegensatz zu anderen Maßnahmen wie Energieberatungen, Fördermitteln und Energiemanagementsystemen als zumindest teilweise wirksame Einflussgröße für die Energieeffizienz. Der Autor empfiehlt auf dieser Basis eine stärker marktwirtschaftlich ausgerichtete Effizienzpolitik.
    Keywords: ddc:330
    Repository Name: Wuppertal Institut für Klima, Umwelt, Energie
    Language: German
    Type: masterthesis , doc-type:masterThesis
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  • 52
    Publication Date: 2022-11-10
    Description: Im Rahmen des Forschungsprojekts "Wirtschaftsförderung 4.0" leistet die vorliegende Arbeit einen Beitrag zum besseren Verständnis der systematischen Stärkung zivilgesellschaftlicher Nachhaltigkeitsinitiativen. Das Ziel der Analyse besteht darin, Ansatzpunkte möglicher Unterstützungsmaßnahmen aufzuzeigen, die im Zuge kommunaler Wirtschaftsförderung aufgegriffen werden können. Zur Erarbeitung wurden zunächst mithilfe theoretischer Grundlagen aus der Transition- und Diffusionsforschung zentrale Einflussfaktoren zusammengetragen, die förderlich oder hemmend auf transformative Nachhaltigkeitsinitiativen wirken können. Mit dem Ziel, kontextangepasste Maßnahmen zu entwickeln, wurden die literaturbasierten Faktoren anschließend in einer qualitativen Befragung mit einer Praxisperspektive verglichen und ergänzt: Mittels leitfadengestützter Experteninterviews mit nachhaltigkeitsorientierten Initiativen in der Region Osnabrück wurden kommunale Gegebenheiten sowie die jeweiligen Erfolgsfaktoren, Herausforderungen und Bedarfe der Graswurzelinitiativen erfasst. Im Ergebnis zeigen sich sieben übergreifende Bedarfsfelder, die vor allem aus der empirischen Erhebung abgeleitet wurden. Aus ihnen wurden Handlungsempfehlungen und Ansatzpunkte kommunaler Unterstützung erarbeitet und diskutiert.
    Keywords: ddc:330
    Repository Name: Wuppertal Institut für Klima, Umwelt, Energie
    Language: German
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  • 53
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    Wuppertal : Wuppertal Institut für Klima, Umwelt, Energie
    Publication Date: 2022-11-09
    Description: Die Autoren verdeutlichen in diesem Papier, dass der Megatrend Digitalisierung nicht zwingend unkontrollierbar über die Wirtschaft und die Gesellschaft hereinbricht. Seine Wirkung hängt vom menschlichen Verhalten, von der Gestaltung neuer Prozessen in Organisationen, aber auch Anpassungen der gesetzlichen Rahmenbedingungen ab. Dieses sozio-kulturelle, organisatorische und institutionelle Umfeld der digitalen Innovationen könne und müsse im Sinne ökologischer Nachhaltigkeit beeinflusst werden. Politik sei hier aufgefordert auf der Basis fundierter Analysen flankierend tätig zu werden. Die Autoren fordern daher, für die Digitalwirtschaft eine eigene sektorspezifische Politik zu entwickeln, wie sie für andere umweltrelevante Sektoren - etwa die Energiewirtschaft, Chemieindustrie oder Autoindustrie - bereits etabliert ist.
    Keywords: ddc:330
    Repository Name: Wuppertal Institut für Klima, Umwelt, Energie
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  • 54
    Publication Date: 2019-06-28
    Description: Using an updated collision model, we conduct a suite of high-resolution N-body integrations to probe the relationship between giant planet mass and terrestrial planet formation and system architecture. We vary the mass of the planets that reside at Jupiter's and Saturn's orbit and examine the effects on the interior terrestrial system.We find that massive giant planets are more likely to eject material from the outer edge of the terrestrial disc and produce terrestrial planets that are on smaller, more circular orbits. We do not find a strong correlation between exterior giant planet mass and the number of Earth analogues (analogous in mass and semi-major axis) produced in the system. These results allow us to make predictions on the nature of terrestrial planets orbiting distant Sun-like star systems that harbour giant planet companions on long orbits - systems that will be a priority for NASA's upcoming Wide-Field Infrared Survey Telescope (WFIRST) mission.
    Keywords: Astrophysics
    Type: GSFC-E-DAA-TN69989 , Monthly Notices of the Royal Astronomical Society (ISSN 0035-8711) (e-ISSN 1365-8711); 485; 1; 541–549
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  • 55
    Publication Date: 2019-05-21
    Description: Recent advances in laboratory spectroscopy lead to the claim of ionized Buckminsterfullerene (C60(+)) as the carrier of two diffuse interstellar bands (DIBs) in the near-infrared. However, irrefutable identication of interstellar C60(+) requires a match between the wavelengths and the expected strengths of all absorption features detectable in the laboratory and in space. Here we present Hubble Space Telescope (HST) spectra of the region covering the C60(+) 9348, 9365, 9428, and 9577 absorption bands toward seven heavily reddened stars. We focus in particular on searching for the weaker laboratory C60(+) bands, the very presence of which has been a matter for recent debate. Using the novel STIS-scanning technique to obtain ultra-high signal-to-noise spectra without contamination from telluric absorption that aficted previous ground-based observations, we obtained reliable detections of the (weak) 9365, 9428 and (strong) 9577 C60(+) bands. The band wavelengths and strength ratios are sufciently similar to those determined in the latest laboratory experiments that we consider this the rst robust identication of the 9428 band, and a conclusive conrmation of interstellar C60(+).
    Keywords: Astrophysics
    Type: GSFC-E-DAA-TN68405 , Astrophysical Journal Letters (ISSN 2041-8205) (e-ISSN 2041-8213); 875; 2; L28
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  • 56
    Publication Date: 2019-05-22
    Description: We present recent high time resolution observations from an oblique (43 deg) shock crossing from the Magnetospheric Multiscale mission. Short-duration bursts between 10 and 100 ms of ion acoustic waves are observed in this event alongside a persistent reflected ion population. High time resolution (150 ms) particle measurements show strongly varying ion distributions between successive measurements, implying that they are bursty and impulsive by nature. Such signatures are consistent with ion bursts that are impulsively reflected at various points within the shock. We find that, after instability analysis using a Fried-Conte dispersion solver, the insertion of dispersive ion bursts into an already stable ion distribution can lead to wave growth in the ion acoustic mode for short durations of time. We find that impulsively reflected ions are a plausible mechanism for ion acoustic wave growth in the terrestrial bow shock and, furthermore, suggest that wave growth can lead to a small but measurable momentum exchange between the solar wind ions and the reflected population.
    Keywords: Astrophysics
    Type: GSFC-E-DAA-TN68433 , Journal of Geophysical Research: Space Physics (e-ISSN 2169-9402); 124; 3; 1855-1865
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  • 57
    Publication Date: 2019-06-29
    Description: We explore the relation between the star formation rate (SFR) surface density (integration of SFR) and the interstellar gas pressure for nearby compact starburst galaxies. The sample consists of 17 green peas and 19 Lyman break analogs (LBAs). Green peas are nearby analogs of Ly alpha emitters at high redshift and LBAs are nearby analogs of Lyman break galaxies at high redshift. We measure the sizes of green peas using Hubble Space Telescope Cosmic Origins Spectrograph near-UV images with a spatial resolution of approximately 0.05 arcsec. We estimate the gas thermal pressure in H II regions by P equals N (sub total)Tk (sub B) approximately or equal to 2n (sub e)Tk (sub B). The electron density is derived using the [S II] doublet at 6716,6731 Angstroms and the temperature is calculated from the [O III] lines. The correlation is characterized by the integration of SFR equals 2.40 times 10 (sup -3) times solar mass per year per square kiloparsec times ((P divided by k (sub B)) divided by (10 ( sup 4) per cubic centimeter times K)) times (sup 1.33). Green peas and LBAs have high integration of SFR up to 1.2 solar masses per year per square kiloparsec and high thermal pressure in the H II region up to P divided by k (sub B) approximating 10 (sup 7.2) K cubic centimeters. These values are at the highest end of the range seen in nearby starburst galaxies. The high gas pressure and the correlation are in agreement with those found instar-forming galaxies at redshift approximating 2.5. These extreme pressures are shown to be responsible for driving galactic winds in nearby starbursts. These outflows may be crucial in enabling Ly alpha and Lyman-continuum to escape.
    Keywords: Astrophysics
    Type: GSFC-E-DAA-TN67881 , Astrophysical Journal (ISSN 2041-8205) (e-ISSN 2041-8213); 872; 2; 146
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  • 58
    Publication Date: 2019-06-28
    Description: We present Keplerian orbit solutions for the mutual orbits of 17 transneptunian binary systems (TNBs). For ten of them, the orbit had not previously been known: 60458 2000 CM (sub 114), 119979 2002 WC (sub 19), 160091 2000 OL (sub 67), 160256 2002 PD (sub 149), 469514 2003 QA (sub 91), 469705 Kagara, 508788 2000 CQ (sub 114), 508869 2002 VT (sub 130), 1999 RT (sub 214), and 2002 XH (sub 91). Seven more are systems where the size, shape, and period of the orbit had been published, but new observations have now eliminated the sky plane mirror ambiguity in its orientation: 90482 Orcus, 120347 Salacia-Actaea, 1998 WW (sub 31), 1999 OJ (sub 4), 2000 QL (sub 251), 2001 XR (sub 254), and 2003 TJ (sub 58). The dynamical masses we obtain from TNB mutual orbits can be combined with estimates of the objects' sizes from thermal observations or stellar occultations to estimate their bulk densities. The Kagara system is currently undergoing mutual events in which one component casts its shadow upon the other and/or obstructs the view of the other. Such events provide valuable opportunities for further characterization of the system. Combining our new orbits with previously published orbits yields a sample of 35 binary orbits with known orientations that can provide important clues about the environment in which outer solar system planetesimals formed, as well as their subsequent evolutionary history. Among the relatively tight binaries, with semimajor axes less than about 5 percent of their Hill radii, prograde mutual orbits vastly outnumber retrograde orbits. This imbalance is not attributable to any known observational bias. We suggest that this distribution could be the signature of planetesimal formation through gravitational collapse of local density enhancements such as caused by the streaming instability. Wider binaries, with semimajor axes greater than 5 percent of their Hill radii, are somewhat more evenly distributed between prograde and retrograde orbits, but with mutual orbits that are aligned or anti-aligned with their heliocentric orbits. This pattern could perhaps result from Kozai-Lidov cycles coupled with tidal evolution eliminating high inclination wide binaries.
    Keywords: Astrophysics
    Type: GSFC-E-DAA-TN68830 , Icarus (ISSN 0019-1035) (e-ISSN 1090-2643)
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  • 59
    Publication Date: 2019-07-02
    Description: We derive direct-measurement gas-phase metallicities of 7.4 〈 12 + log(O/H) 〈 8.4 for 14 low-mass emission- line galaxies at 0.3 〈 z 〈 0.8 identied in the Faint Infrared Grism Survey. We use deep slitless G102 grism spectroscopy of the Hubble Ultra Deep Field, dispersing light from all objects in the eld at wavelengths between 0.85 and 1.15 m. We run an automatic search routine on these spectra to robustly identify 71 emission-line sources, using archival data from Very Large Telescope (VLT)/Multi-Unit Spectroscopic Explorer (MUSE) to measure additional lines and conrm redshifts. We identify 14 objects with 0.3 〈 z 〈 0.8 with measurable [O III] 4363 emission lines in matching VLT/MUSE spectra. For these galaxies, we derive direct electron-temperature gas-phase metallicities with a range of 7.4 〈 12 + log(O/H) 〈 8.4. With matching stellar masses in the range of 10(exp 7.9) Solar Mass 〈 M(sub *) 〈 10(exp 10.4) Solar Mass, we construct a massmetallicity (MZ) relation and nd that the relation is offset to lower metallicities compared to metallicities derived from alternative methods (e.g., R(sub 23), O3N2, N2O2) and continuum selected samples. Using star formation rates derived from the H emission line, we calculate our galaxies position on the Fundamental Metallicity Relation, where we also nd an offset toward lower metallicities. This demonstrates that this emission-line-selected sample probes objects of low stellar masses but even lower metallicities than many comparable surveys. We detect a trend suggesting galaxies with higher Specic Star Formation (SSFR) are more likely to have lower metallicity. This could be due to cold accretion of metal-poor gas that drives star formation, or could be because outows of metal-rich stellar winds and SNe ejecta are more common in galaxies with higher SSFR.
    Keywords: Astrophysics
    Type: GSFC-E-DAA-TN68614 , Astrophysical Journal (ISSN 0004-637X) (e-ISSN 1538-4357); 874; 2; 125
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  • 60
    Publication Date: 2019-07-02
    Description: No abstract available
    Keywords: Spacecraft Propulsion and Power
    Type: MSFC-E-DAA-TN70022
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  • 61
    Publication Date: 2019-07-02
    Description: The gas metallicity of galaxies is often estimated using strong emission lines such as the optical lines of [O iii] and [O ii]. The most common measure is "R23," defined as ([O ii]3726, 3729 + [O iii]4959,5007)/H. Most calibrations for these strong-line metallicity indicators are for continuum selected galaxies. We report a new empirical calibration of R23 for extreme emission-line galaxies using a large sample of about 800 star-forming green pea galaxies with reliable Te -based gas-phase metallicity measurements. This sample is assembled from Sloan Digital Sky Survey (SDSS) Data Release 13 with the equivalent width of the line [O iii]5007 〉 300 or the equivalent width of the line H 〉 100 in the redshift range 0.011 〈 z 〈 0.411. For galaxies with strong emission lines and large ionization parameter (which manifests as log [O iii]4959,5007/[O ii]3726,3729 0.6), R23 monotonically increases with log(O/H) and the double-value degeneracy is broken. Our calibration provides metallicity estimates that are accurate to within ~0.14 dex in this regime. Many previous R23 calibrations are found to have bias and large scatter for extreme emission-line galaxies. We give formulae and plots to directly convert R23 and [O iii]4959,5007/[O ii]3726,3729 to log(O/H). Since green peas are best nearby analogs of high-redshift Ly emitting galaxies, the new calibration offers a good way to estimate the metallicities of both extreme emission-line galaxies and high-redshift Ly emitting galaxies. We also report on 15 galaxies with metallicities less than 1/12 solar, with the lowest metallicities being 12+log(O/H) = 7.25 and 7.26.
    Keywords: Astrophysics
    Type: GSFC-E-DAA-TN67882 , Astrophysical Journal (ISSN 0004-637X) (e-ISSN 1538-4357); 872; 2; 145
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  • 62
    Publication Date: 2019-05-23
    Description: NASA is committed to a sustainable return of humans to the Moon for long-term exploration and utilization. Gateway will enable this sustained cis-lunar presence and provide the capabilities necessary to develop and deploy critical infrastructure.
    Keywords: Spacecraft Propulsion and Power
    Type: GRC-E-DAA-TN67049
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  • 63
    Publication Date: 2019-05-18
    Description: We describe an approach to build an x-ray mirror assembly that can meet Lynxs requirements of high-angular resolution, large effective area, light weight, short production schedule, and low-production cost. Adopting a modular hierarchy, the assembly is composed of 37,492 mirror segments, each of which measures 100 mm 100 mm 0.5 mm. These segments are integrated into 611 modules, which are individually tested and qualified to meet both science performance and spaceflight environment requirements before they in turn are integrated into 12 metashells. The 12 metashells are then integrated to form the mirror assembly. This approach combines the latest precision polishing technology and the monocrystalline silicon material to fabricate the thin and lightweight mirror segments. Because of the use of commercially available equipment and material and because of its highly modular and hierarchical building-up process, this approach is highly amenable to automation and mass production to maximize production throughput and to minimize production schedule and cost. As of fall 2018, the basic elements of this approach, including substrate fabrication, coating, alignment, and bonding, have been validated by the successful building and testing of single-pair mirror modules. In the next few years, the many steps of the approach will be refined and perfected by repeatedly building and testing mirror modules containing progressively more mirror segments to fully meet science performance, spaceflight environments, as well as programmatic requirements of the Lynx mission and other proposed missions, such as AXIS.
    Keywords: Astrophysics
    Type: GSFC-E-DAA-TN68353 , Journal of Astronomical Telescopes, Instruments, and Systems; 5; 2; 021012
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  • 64
    Publication Date: 2019-07-31
    Description: Alpha Centauri AB system contains the closest Sun-like stars to the Sun, by a large margin (factor of 2.4). Thus, they are important targets for the search of Earth-like planets. A critical question is whether such planets can exist in the system, and what their expected occurrence rate is. This paper surveys the current knowledge of occurrence rates, limits from nondetections, constraints from observations, and dynamical stability simulations, in order to answer this question.
    Keywords: Astrophysics
    Type: ARC-E-DAA-TN69636 , AbSciCon 2019; Jun 24, 2019 - Jun 28, 2019; Bellevue, WA; United States
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  • 65
    Publication Date: 2019-06-26
    Description: This release note discusses the science data products produced by the Science Processing Operations Center at Ames Research Center from Sector 9 observations made with the TESS spacecraft and cameras as a means to document instrument performance and data characteristics.
    Keywords: Astrophysics
    Type: ARC-E-DAA-TN69031
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  • 66
    Publication Date: 2019-06-26
    Description: This release note discusses the science data products produced by the Science Processing Operations Center at Ames Research Center from Sector 10 observations made with the TESS spacecraft and cameras as a means to document instrument performance and data characteristics.
    Keywords: Astrophysics
    Type: NASA/TM-2019-220220 , ARC-E-DAA-TN69634
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  • 67
    Publication Date: 2019-06-20
    Description: Enabled by the Fermi Large Area Telescope, we now know young and recycled pulsars fill the gamma-ray sky, and we are beginning to understand their emission mechanism and their distribution throughout the Galaxy. However, key questions remain: Is there a large population of pulsars near the Galactic center? Why do the most energetic pulsars shine so brightly in MeV gamma rays but not always at GeV energies? What is the source and nature of the pair plasma in pulsar magnetospheres, and what role does the polar cap accelerator play? Addressing these questions calls for a sensitive, wide-field MeV telescope, which can detect the population of MeV-peaked pulsars hinted at by Fermi and hard X-ray telescopes and characterize their spectral shape and polarization.
    Keywords: Astrophysics
    Type: GSFC-E-DAA-TN69835
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  • 68
    Publication Date: 2019-08-03
    Description: The processes leading to the formation of planets; the extreme physics occurring near the event horizon of black holes; detailed studies of exoplanets through spectral-spatial mapping: new and unique insights into the physical processes involved across nearly the whole gamut of astrophysics await discovery at small angular scales. The fine spatial resolution needed to explore these processes, however, lies beyond the capabilities of current astronomical facilities and nearly all proposed future facilities. Interferometers can crack this angular resolution problem, and space-based interferometry missions promise to explore entirely new regions of scientific phase space, providing unique new insights into the physical processes lurking at small angular scales.
    Keywords: Astrophysics
    Type: GSFC-E-DAA-TN70915
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  • 69
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    Unknown
    In:  CASI
    Publication Date: 2019-07-20
    Description: No abstract available
    Keywords: Astrophysics
    Type: MSFC-E-DAA-TN64281 , Meeting of the American Astronomical Society; Jan 06, 2019 - Jan 10, 2019; Seattle, WA; United States
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  • 70
    Publication Date: 2019-07-20
    Description: No abstract available
    Keywords: Spacecraft Propulsion and Power
    Type: MSFC-E-DAA-TN63467 , Lecture at the International Space University; Jan 24, 2019; Strasbourg; France
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  • 71
    Publication Date: 2019-07-20
    Description: No abstract available
    Keywords: Astrophysics
    Type: MSFC-E-DAA-TN64478 , American Astornomical Society (AAS) Meeting; Jan 06, 2019 - Jan 10, 2019; Seattle, WA; United States
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  • 72
    Publication Date: 2019-07-20
    Description: We describe a probe-class mission concept that provides an unprecedented view of the X-ray sky, performing timing and 0.2-30 keV spectroscopy over timescales from microseconds to years. The Spectroscopic Time-Resolving Observatory for Broadband Energy X-rays (STROBE-X) has three key science drivers: (1) measuring the spin distribution of accreting black holes, (2) understanding the equation of state of dense matter, and (3) exploring the properties of the precursors and electromagnetic counterparts of gravitational wave sources. To perform these science investigations, STROBE-X comprises three primary instruments. The first uses an array of lightweight optics (3-m focal length) that concentrate incident photons onto solid state detectors with CCD-level (85-130 eV) energy resolution, 100 ns time resolution, and low background rates to cover the 0.2-12 keV band. This technology is scaled up from NICER, with enhanced optics to take advantage of the longer focal length of STROBE-X. The second uses large-area collimated silicon drift detectors, developed for ESA's LOFT, to cover the 2-30 keV band. These two instruments each provide an order of magnitude improvement in effective area compared with its predecessor (NICER and RXTE, respectively). Finally, a sensitive sky monitor triggers pointed observations, provides high duty cycle, high time resolution, high spectral resolution monitoring of the X-ray sky with ~20 times the sensitivity of the RXTE ASM, and enables multi-wavelength and multi-messenger studies on a continuous, rather than scanning basis. The STROBE-X mission concept is a rapidly repointable observatory in low-Earth orbit, similar to RXTE or Swift, and will be presented to the 2020 Astrophysics Decadal Survey for consideration as a probe-class mission.
    Keywords: Astrophysics
    Type: MSFC-E-DAA-TN64215 , Meeting of the American Astronomical Society (AAS); Jan 06, 2019 - Jan 10, 2019; Seattle,WA; United States
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  • 73
    Publication Date: 2019-07-20
    Description: A series of short-duration (200 h) wear tests were conducted with two Hall Effect Rocket with Magnetic Shielding (HERMeS) technology demonstration units. Front pole covers, cathode keeper, and discharge channel wear were characterized as a function of discharge voltage, magnetic field strength, and chamber pressure. No discharge channel erosion was observed. Inner pole cover erosion was shown to be a weak function of discharge voltage with most erosion occurring at the lowest value, 300 V. The Technology Demonstration Unit (TDU) 3 keeper electrode eroded with each operating condition, with high magnetic field yielding the greatest erosion rate. The TDU-1 keeper electrode exhibited net deposition suggesting its configuration is more consistent with meeting overall HERMeS service life requirements. Ratios of molybdenum to graphite erosion rates suggests, with high uncertainty, that the sputtering ions are originating downstream of the thruster exit plane, striking the surface with small angles of incidence.
    Keywords: Spacecraft Propulsion and Power
    Type: NASA/TM-2019-219731 , IEPC?2017?207 , E-19456 , GRC-E-DAA-TN48801 , International Electric Propulsion Conference; Oct 08, 2017 - Oct 12, 2017; Atlanta, GA; United States
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  • 74
    Publication Date: 2019-07-20
    Description: No abstract available
    Keywords: Spacecraft Propulsion and Power
    Type: M19-7187 , IEEE Aerospace Conference; Mar 03, 2019 - Mar 08, 2019; Big Sky, MT; United States
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  • 75
    Publication Date: 2019-07-20
    Description: Recent trades have taken place on solid propulsion options to support a potential Mars Sample Retrieval Campaign. Mass and dimensional requirements for a Mars Ascent Vehicle (MAV) are being assessed. One MAV vehicle concept would utilize a solid propulsion system. Key challenges to designing a solid propulsion system for MAV include low temperatures beyond common tactical and space requirements, performance, planetary protection, mass limits, and thrust vector control system. Two solutions are addressed, a modified commercial commercially available system, and an optimum new concept.
    Keywords: Spacecraft Propulsion and Power
    Type: M18-7069 , IEEE Aerospace Conference; Mar 02, 2019 - Mar 09, 2019; Big Sky, MT; United States
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  • 76
    Publication Date: 2019-07-20
    Description: Technology for a hybrid based propulsion system is being developed to support a potential Mars Sample Return campaign. A Mars Ascent Vehicle (MAV) concept for launching samples off of Mars, and delivering them to orbit for further transport to Earth may utilize hybrid propulsion due to the predicted favorable low temperature characteristics and high performance of this option. However, the hybrid option is still undergoing technology development to demonstrate these capabilities. Once development of a capable hybrid propulsion system is proven, further work will be required. This will include environmental testing relative to the mission, and integration with the vehicle reaction control systems and payload. Qualification of such a system will be a significant effort. It will require specialized procurements for the propellants and environments involved, and further testing of the more specialized designs. This paper details an estimate of the tasks required to complete development efforts from Technical Readiness Level 5 (TRL5) through qualification. A success based program was formulated to reach the required performance metrics sufficient for a standard Preliminary Design Review (PDR). Using task level inputs from team members cost and schedule were conceived for continued progress to Critical Design Review (CDR), then through Qualification.
    Keywords: Spacecraft Propulsion and Power
    Type: M18-7041 , IEEE Aerospace Conference; Mar 02, 2019 - Mar 09, 2019; Big Sky, MT; United States
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  • 77
    Publication Date: 2019-07-20
    Description: The Advanced Concepts Office (ACO) at Marshall Space Flight Center (MSFC) has conducted ongoing studies and trades into options for both hybrid and solid vehicle systems for potential Mars Ascent Vehicle (MAV) concepts for the Jet Propulsion Laboratory (JPL). Two MAV propulsion options are being studied for use in a potential Mars Sample Retrieval (MSR) campaign. The following paper describes the current concepts for hybrid and solid propulsion vehicles for MAV as part of a potential MSR campaign, and provides an overview of the ongoing studies and trades for both hybrid and solid vehicle system concepts. Concepts and options under consideration for vehicle subsystems include reaction control system (RCS), separation, and structures will be described in terms of technology readiness level (TRL), benefit to the vehicle design, and associated risk. A hybrid propulsion system, which uses a solid fuel core and liquid oxidizer, is currently being developed by JPL with support from MSFC. This type of hybrid propulsion vehicle would allow the MAV to be more flexible at the cost of higher complexity, in contrast to the solid propulsion vehicle that is simpler, but allows less flexibility. The solid propulsion vehicle study performed by MSFC in 2018 further refined the solid propulsion system sizing as well as added definition to vehicle subsystem concepts, including the RCS, structures and configuration, interstage and separation, aerodynamics, and power/avionics. The studies were performed using an iterative concept design methodology, engaging subject matter experts from across MSFCs propulsion and vehicle systems disciplines as well as seeking trajectory feedback from analysts at JPL.
    Keywords: Spacecraft Propulsion and Power
    Type: M18-7053 , 2019 IEEE Aerospace Conference; Mar 02, 2019 - Mar 09, 2019; Big Sky, MT; United States
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  • 78
    Publication Date: 2019-07-20
    Description: An approach is presented supporting analysis, modeling, and test validation of operational flight instrumentation (OFI) that facilitates critical functions for the Space Launch System (SLS) main propulsion system (MPS). Certain types of OFI sensors were shown to exhibit highly nonlinear and non-gaussian noise characteristics during acceptance testing, motivating the development of advanced modeling and simulation (M&S) capability to support algorithm verification and flight certification. Hardware model and algorithm simulation fidelity was informed by a risk scoring metric; redesign of high-risk algorithms using test-validated sensor models significantly improved their expected performance as evaluated using Monte Carlo acceptance sampling methods. Autonomous functions include closed-loop ullage pressure regulation, pressurant leak detection, and fault isolation for automated safing and crew caution and warning (C&W).
    Keywords: Spacecraft Propulsion and Power
    Type: AAS 19-103 , M19-7260 , Annual AAS Guidance and Control Conference; Feb 01, 2019 - Feb 06, 2019; Breckenridge, CO; United States
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  • 79
    Publication Date: 2019-07-20
    Description: The work presented here sought to explore a portion of the parameter space of a hybrid nuclear fuel in regards to ignition and burn by analyzing the effect of initial geometry and thermodynamic conditions. The authors performed 0D power balance and 1D burn wave calculations to determine temperature progression and energy production for defined initial conditions. Geometries examined are representative of concept fuels for a Pulsed Fission-Fusion (PuFF) engine. This work focuses on lithium deuteride and uranium 235 for the fuel since these are seen as leading candidates for PuFF. Presented below is a power balance illustrating a reduction in the energy and density required to breakeven of hybrid fuels in comparison with fusion fuels. Also the impact of fusion and fissile fuel quantities upon initial energies is presented. One can see that the initial energy required to breakeven in a hybrid cylindrical nuclear fuel decreases with decreasing fissile liner thickness, decreasing fusion fuel core radius, and increasing compression ratio of the fusion fuel.
    Keywords: Spacecraft Propulsion and Power
    Type: M19-7200 , NETS Nuclear and Emerging Technologies for Space 2019; Feb 25, 2019 - Feb 28, 2019; Richland, WA; United States
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  • 80
    Publication Date: 2019-07-20
    Description: The high-energy universe has revealed that energetic particles are ubiquitous in the cosmos and play a vital role in the cultivation of cosmic environments on all scales. Our pursuit of more than a century to uncover the origins and fate of these cosmic energetic particles has given rise to some of the most interesting and challenging questions in astrophysics. Energetic particles in our own galaxy, galactic cosmic rays (GCRs), engage in a complex interplay with the interstellar medium and magnetic fields in the galaxy, giving rise to many of its key characteristics. For instance, GCRs act in concert with galactic magnetic fields to support its disk against its own weight. GCR ionization and heating are essential ingredients in promoting and regulating the formation of stars and protostellar disks. GCR ionization also drives astrochemistry, leading to the build up of complex molecules in the interstellar medium. GCR transport throughout the galaxy generates and maintains turbulence in the interstellar medium, alters its multi-phase structure, and amplifies magnetic fields. GCRs could even launch galactic winds that enrich the circumgalactic medium and alter the structure and evolution of galactic disks. As crucial as they are for many of the varied phenomena in our galaxy, there is still much we do not understand about GCRs. While they have been linked to supernova remnants (SNRs), it remains unclear whether these objects can fully account for their entire population, particularly at the lower (approximately less than 1 GeV per nucleon) and higher (~PeV) ends of the spectrum. In fact, it is entirely possible that the SNRs that have been found to accelerate CRs merely re-accelerate them, leaving the origins of the original GCRs a mystery. The conditions for particle acceleration that make SNRs compelling source candidates are also likely to be present in sources such as protostellar jets, superbubbles, and colliding wind binaries (CWBs), but we have yet to ascertain their roles in producing GCRs. For that matter, key details of diffusive shock acceleration (DSA) have yet to be revealed, and it remains to be seen whether DSA can adequately explain particle acceleration in the cosmos. This White Paper is the first of a two-part series highlighting the most well-known high-energy cosmic accelerators and contributions that MeV gamma-ray astronomy will bring to understanding their energetic particle phenomena. For the case of GCRs, MeV astronomy will: 1) Search for fresh acceleration of GCRs in SNRs; 2) Test the DSA process, particularly in SNRs and CWBs; 3) Search for signs of CR acceleration in protostellar jets and superbubbles.
    Keywords: Astrophysics
    Type: GSFC-E-DAA-TN66970
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  • 81
    Publication Date: 2019-07-19
    Description: Improving protection and health management capabilities onboard the electrical power system (EPS) for spacecraft is essential for ensuring safe and reliable conditions for deep space human exploration. Electrical protection and control technologies on the National Aeronautics and Space Administration's (NASA's) current human space platform relies heavily on ground support to monitor and diagnose power systems and failures. As communication bandwidth diminishes for deep space applications, a transformation in system monitoring and control becomes necessary to maintain high reliability of electric power service. This paper presents a novel approach for on-line power system security monitoring for autonomous deep space spacecraft.
    Keywords: Spacecraft Propulsion and Power
    Type: GRC-E-DAA-TN63587 , GRC-E-DAA-TN57847 , AIAA SciTech Forum 2019; Jan 07, 2019 - Jan 11, 2019; San Diego, CA; United States
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  • 82
    Publication Date: 2019-07-20
    Description: The Kepler Mission launched in June 2009 to commence NASA's first mission to search for potentially habitable, Earth-size planets orbiting Sun-like stars. Kepler discovered explanets via the transit method: searching for minute (100 ppm) drops in brightness lasting 1 - 13 hours corresponding to occasions where the planet crosses the face of its host star from Kepler's point of view. The exquisite precision required to carry out the Kepler mission (20 ppm in 6.5 hours) pushed astronomical time series analysis to the limits, and motivated the development of novel algorithmic approaches. Transit signatures of rocky planets are often dwarfed by the intrinsic stellar variability, which is not white noise, and often is non-stationary, and by instrumental systematic effects, which can include transients and electronic artifacts. Surmounting this challenging regime of weak, temporally compact, periodic signals in observation noise with strong systematics and other sources of variability motivated the development of 1) an overcomplete, non-decimated, wavelet-based matched filter to jointly estimate the properties of the non-stationary, non-white observation noise process, and 2) a multi-scale, maximum a posteriori (msMAP) approach to identifying and removing instrumental systematic effects. After over nine years of observations, the Kepler spacecraft finally ran out of fuel in November 2018, ending its data collection activities. Over 2300 planets were discovered by Kepler in its primary mission, and over 355 have been discovered by K2, the repurposed mission that followed Kepler's primary mission after the loss of a second reaction wheel in May 2013. We have ported the Kepler science pipeline for the Transiting Exoplanet Survey Satellite (TESS) Mission, which began science observations in July 2019, and report initial results and performance of the modified science pipeline.The Kepler and TESS Missions are supported by NASA's Science Mission Directorate.
    Keywords: Astrophysics
    Type: ARC-E-DAA-TN63583 , Astronomical Time Series 2019 (NCTS 37182-19); Jan 21, 2019 - Jan 24, 2019; Heidelberg; Germany
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  • 83
    Publication Date: 2019-07-20
    Description: Studying the physical processes occurring in the region just above the magnetic polesof strongly magnetized, accreting binary neutron stars is essential to our understanding of stellarand binary system evolution. Perhaps more importantly, it provides us with a natural laboratoryfor studying the physics of high temperature and density plasmas exposed to extreme radiation,gravitational, and magnetic fields. Observations over the past decade have shed new light on themanner in which plasma falling at near the speed of light onto a neutron star surface is halted. Recentadvances in modeling these processes have resulted in direct measurement of the magnetic fieldsand plasma properties. On the other hand, numerous physical processes have been identified thatchallenge our current picture of how the accretion process onto neutron stars works. Observationand theory are our essential tools in this regime because the extreme conditions cannot be duplicatedon Earth. This white paper gives an overview of the current theory, the outstanding theoreticaland observational challenges, and the importance of addressing them in contemporary astrophysicsresearch.
    Keywords: Astrophysics
    Type: GSFC-E-DAA-TN66958
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  • 84
    Publication Date: 2019-07-20
    Description: One of the most notable developments since the 2010 Decadal Survey is the addition of gravitationalwaves (GW) to the astronomers' suite of tools for understanding the Universe. LIGO's2015 detection of gravitational waves (Abbott et al. 2016) from the merger of a pair of black holesroughly 30 times the mass of our Sun garnered tremendous excitement from both the public andthe scientific community and raised interesting questions as to the origin of such systems. To datea total of 11 confirmed detections have been announced, including the first GW signals from themerger of neutron stars in 2017 seen by LIGO and Virgo (Abbott et al. 2017). That event wasassociated with a gamma ray burst; the subsequent kilonovae and afterglow was perhaps the mostthoroughly-observed astronomical event of all time (Abbott et al. 2017b). In the coming decades,with continued investment, the ground-based network will continue to improve in both the numberand sensitivity of detectors at high frequencies, pulsar timing arrays such as NANOGrav willuncover stochastic sources of gravitational waves and then single sources at low frequencies, andLISA will begin to probe the mid-frequency band from space. In this white paper, we presenta broad outline of the scientific impact of these facilities in the coming decade and the 2030s,emphasizing the ways in which
    Keywords: Astrophysics
    Type: GSFC-E-DAA-TN66963
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  • 85
    Publication Date: 2019-07-20
    Description: The RAMPT project is maturing novel design and manufacturing technologies to increase scale, significantly reduce cost, and improve performance for regeneratively-cooled thrust chamber assemblies, specifically the combustion chamber and nozzle for government and industry programs.
    Keywords: Spacecraft Propulsion and Power
    Type: MSFC-E-DAA-TN66349
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  • 86
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    Unknown
    In:  CASI
    Publication Date: 2019-07-20
    Description: No abstract available
    Keywords: Astrophysics
    Type: MSFC-E-DAA-TN64284 , American Astronomical Society Meeting; Jan 06, 2019 - Jan 10, 2019; Seattle, WA; United States
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  • 87
    Publication Date: 2019-07-20
    Description: Low-frequency gravitational-wave astronomy can perform precision tests of general relativity and probe fundamental physics in a regime previously inaccessible. A space-based detector will be a formidable tool to explore gravity's role in the cosmos, potentially telling us if and where Einstein's theory fails and providing clues about some of the greatest mysteries in physics and astronomy, such as dark matter and the origin of the Universe.
    Keywords: Astrophysics
    Type: GSFC-E-DAA-TN67178 , GSFC-E-DAA-TN66949
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  • 88
    Publication Date: 2019-07-20
    Description: Pulsar timing arrays (PTAs) are on the verge of detecting low-frequency gravitational waves (GWs)from supermassive black hole binaries (SMBHBs). With continued observations of a large sampleof millisecond pulsars, PTAs will reach this major milestone within the next decade. Already,SMBHB candidates are being identied by electromagnetic surveys in ever-increasing numbers;upcoming surveys will enhance our ability to detect and verify candidates, and will be instrumentalin identifying the host galaxies of GW sources. Multi-messenger (GW and electromagnetic) obser-vations of SMBHBs will revolutionize our understanding of the co-evolution of SMBHs with theirhost galaxies, the dynamical interactions between binaries and their galactic environments, and thefundamental physics of accretion. Multi-messenger observations can also make SMBHBs `standardsirens' for cosmological distance measurements out to z ~ 0.5 LIGO has already ushered in break-through insights in our knowledge of black holes. The multi-messenger detection of SMBHBs withPTAs will be a breakthrough in the years 2020-2030 and beyond, and prepare us for LISA to helpcomplete our views of black hole demographics and evolution at higher redshifts.
    Keywords: Astrophysics
    Type: GSFC-E-DAA-TN66951
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  • 89
    Publication Date: 2019-07-20
    Description: LISA will open the mHz band of gravitational waves (GWs) to the astronomy community. Thestrong gravity which powers the variety of GW sources in this band is also crucial in a numberof important astrophysical processes at the current frontiers of astronomy. These range fromthe beginning of structure formation in the early universe, through the origin and cosmic evolutionof massive black holes in concert with their galactic environments, to the evolution ofstellar remnant binaries in the Milky Way and in nearby galaxies. These processes and theirassociated populations also drive current and future observations across the electromagnetic(EM) spectrum. We review opportunities for science breakthroughs, involving either direct coincidentEM+GW observations, or indirect multimessenger studies. We argue that for the UScommunity to fully capitalize on the opportunities from the LISA mission, the US efforts shouldbe accompanied by a coordinated and sustained program of multi-disciplinary science investment,following the GW data through to its impact on broad areas of astrophysics. Supportfor LISA-related multimessenger observers and theorists should be sized appropriately for aflagship observatory and may be coordinated through a dedicated mHz GW research center.
    Keywords: Astrophysics
    Type: GSFC-E-DAA-TN66947
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  • 90
    Publication Date: 2019-07-20
    Description: This paper looks at the key programmatic and technical drivers of the James Webb Space Telescope and assesses ways to building more cost-effective telescopes in the future. The paper evaluates the top level programmatics for JWST along with the key technical drivers from design through integration and testing. Actual data and metrics from JWST are studied to identify what ultimately drove cost on JWST. Finally, the paper assesses areas where applying lessons learned can reduce costs on future observatories and will provide better insights into critical areas to optimize for cost.
    Keywords: Astrophysics
    Type: GSFC-E-DAA-TN65820
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  • 91
    Publication Date: 2019-07-20
    Description: The high-energy universe has revealed that energetic particles are ubiquitous in the cosmos and play a vital role in the cultivation of cosmic environments on all scales. Our pursuit of more than a century to uncover the origins and fate of these cosmic energetic particles has given rise to some of the most interesting and challenging questions in astrophysics. Within our own galaxy, we have seen that energetic particles engage in a complex interplay with the galactic environment and even drive many of its key characteristics (for more information, see the first white paper in this series). On cosmological scales, the energetic particles supplied by the jets of active galactic nuclei (AGN) are an important source of energy for the intracluster and intergalactic media, providing a mechanism for regulating star formation and black hole growth and cultivating galaxy evolution (AGN feedback). Gamma-ray burst (GRB) afterglows encode information about their circumburst environment, which has implications for massive stellar winds during previous epochs over the stellar lifecycle. As such, GRB afterglows provide a means for studying very high-redshift galaxies since GRBs can be detected even if their host galaxy cannot. It has even been suggest that GRB could be used to measure cosmological distance scales if they could be shown to be standard candles. Though they play a key role in cultivating the cosmological environment and/or enabling our studies of it, there is still much we do not know about AGNs and GRBs, particularly the avenue in which and through which they supply radiation and energetic particles, namely their jets. Despite the enormous progress in particle-in-cell and magnetohydrodynamic simulations, we have yet to pinpoint the processes involved in jet formation and collimation and the conditions under which they can occur. For that matter, we have yet to identify the mechanism(s) through which the jet accelerates energetic particles is it the commonly invoked diffusive shock acceleration process or is another mechanism, such as magnetic reconnection, required? Do AGNs and GRBs accelerate hadrons, and if so, do they accelerate them to ultra-high energies and are there high-energy neutrinos associated with them? MeV gamma-ray astronomy, enabled by technological advances that will be realized in the coming decade, will provide a unique and indispensable perspective on the persistent mysteries of the energetic universe. This White Paper is the second of a two-part series highlighting the most well-known high-energy cosmic accelerators and contributions that MeV gamma-ray astronomy will bring to understanding their energetic particle phenomena. Specifically, MeV astronomy will: 1. Determine whether AGNs accelerate CRs to ultra-high energies; 2. Provide the missing pieces for the physics of the GRB prompt emission; 3. Measure magnetization in cosmic accelerators and search for acceleration via reconnection.
    Keywords: Astrophysics
    Type: GSFC-E-DAA-TN66972
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  • 92
    Publication Date: 2019-07-20
    Description: In preparation for the 2020 Decadal Survey in Astronomy and Astrophysics, NASA commissioned the study of four large mission concepts: the Large UV/Optical/Infrared Surveyor (LUVOIR), the Habitable Exoplanet Imager (HabEx), the far-infrared surveyor Origins Space Telescope (OST), and the X-ray surveyor Lynx. The LUVOIR Science and Technology Definition Team (STDT) has identified a broad range of science objectives for LUVOIR that include the direct imaging and spectral characterization of habitable exoplanets around sun-like stars, the study of galaxy formation and evolution, the exchange of matter between galaxies, star and planet formation, and the remote sensing of Solar System objects. The LUVOIR Study Office, located at NASA's Goddard Space Flight Center (GSFC), is developing two mission concepts to achieve the science objectives. LUVOIR-A is a 15-meter segmented-aperture observatory that would be launched in an 8.4-m extended fairing on the Space Launch System (SLS) Block 2 configuration. LUVOIR-B is an 8-meter unobscured segmented aperture telescope that fits in a smaller, conventional 5-meter fairing, but still requires the lift capacity of the SLS Block 1B Cargo vehicle. Both concepts include a suite of serviceable instruments: the Extreme Coronagraph for Living Planetary Systems (ECLIPS), an optical/near-infrared coronagraph capable of delivering 10 (sup minus10) contrast at inner working angles as small as 2 lambda divided by D; the LUVOIR UV Multi-object Spectrograph (LUMOS), which will provide low- and medium-resolution UV (100-400 nanometer) multi-object imaging spectroscopy in addition to far-UV imaging; the High Definition Imager (HDI), a high-resolution wide-field-of-view NUV-Optical-NIR imager. LUVOIR-A also has a fourth instrument, Pollux, a high-resolution UV spectro-polarimeter being contributed by Centre National d'Etudes Spatiales (CNES). This paper provides an overview of the LUVIOR science objectives, design drivers, and mission concepts.
    Keywords: Astrophysics
    Type: GSFC-E-DAA-TN65070 , IEEE Aerospace Conference (AeroConf 2019); 2ý9 Mar. 2019; Big Sky, MT; United States
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  • 93
    Publication Date: 2019-07-20
    Description: NASA space missions have long employed Radioisotope Power Systems (RPS) and solar-based power generation architectures. RPS have been used to enable or significantly enhance missions that venture deep into the solar system to distances from the sun which can make using solar architectures unfeasible and to areas where the sun is obscured due to shadows or atmospheric phenomena. The destination, however, is not the absolute factor of the determination of RPS or solar. This is highlighted by the Jupiter missions Galileo and Juno, which employed RPS and solar architectures, respectively. When baselining either RPS or solar architectures for a planetary mission, numerous factors must be considered, including scientific objectives, cost, schedule, and mass just to name a few. In an effort to better understand the decision-making process and provide insight for potential future missions, the NASA RPS Program Office tasked The Aerospace Corporation (Aerospace) to study historical missions that used RPS and solar architectures. Data was collected for a variety of RPS and solar missions to look for possible trends from the selected implementation. Additionally, mission case studies were developed based on interviews with mission personnel who were responsible for defining the power architecture of their mission. Informed by the data collected and case studies, two Measures of Effectiveness (MoEs) were produced: one based on cost of RPS versus solar, and one based on science mission cost effectiveness. The final results of this study have been captured in this briefing package which is available for full and open release. Additionally, a final report document also provides the same details of this package. This briefing package also includes an appendix which contains data not for public release which was used to provide detailed answers to questions raised during this study. The results of these inquiries are discussed in the report, but the proprietary data is not included. Finally, an executive summary package is also publicly available which was used to present the results of the study at the 2018 Aerospace Space Power Workshop.
    Keywords: Spacecraft Propulsion and Power
    Type: NASA/CR-2019-220039 , ATR-2018-02688 , GRC-E-DAA-TN62337
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  • 94
    Publication Date: 2019-07-20
    Description: Power production is a key aspect to any Mars mission. One method for providing power throughout the day/night cycle, or to satisfy short-duration high-output power needs, is to utilize a regenerative fuel cell system for providing energy storage and nighttime or supplemental power. This study compares the total system mass for two types of fuel cell systems, proton exchange membrane (PEM) and solid oxide (SO), sized to provide 10 kW of electrical output power in the Mars environment. Two operating locations were examined; one near the equator at 4 S latitude and one the higher northern latitude of 48N. The systems were sized to operate throughout the year at these locations, where the radiator was sized for the worst-case warm condition and the insulation was sized for the worst-case cold condition. Using the selected system parameters, the results for both latitudes showed that the lightest system was the SO fuel cell with a PEM electrolyzer. This was mainly due to the higher operational temperature of the SO system enabled a significantly smaller radiator mass compared to that of the PEM fuel cell system. However, there was a significant difference in mass for the PEM system when operated near the equator as compared to the higher northern latitude. For the 10-kW output system this difference in mass was just under 100 kg.
    Keywords: Spacecraft Propulsion and Power
    Type: GRC-E-DAA-TN62192 , NASA/TM-2019-220019
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  • 95
    Publication Date: 2019-07-20
    Description: When is it advantageous to assemble telescopes in space rather than deploying them from launch vehicle fairings? This question forms the crux of the objectives of a NASA study we have been conducting in collaboration with colleagues from different NASA centers, industry and academia. In this study, we have engaged a broad cross section of experts from the various fields of optics engineering, that is, telescope design and instrument design, structure and thermal engineering, robotics, launch system engineering, orbital mechanics, integration and testing, astrophysics, and NASA programmatics among others. Initial efforts began with a quick review of the current state of art of the component technologies that contribute towards an in-space assembled telescope. Then, leveraging the collective expertise of the diverse group of experts, we formulated a reference telescope design and attempted to develop a baseline approach to modularize the telescope into components amenable for robotic assembly. The group identified different trades associated with modularization and also developed a set of criteria to discern between the different options as revealed by the trades. Based on the modularization of the telescope, we will assess the impact of various launch vehicles, orbits for assembly and operation, robotic systems and operational approaches, and other related variables. From this, a concept to assemble the reference telescope in space from modular components will be developed. Based on this concept, and definition of the modules, we will develop a mission lifecycle plan for an assembled telescope over different phases of preliminary design, detailed design, assembly-test-and-integration, and in space operations. The mission lifecycle plan will be used to evaluate cost and risk implications of in-space assembly toward answering our fundamental question of the advantages, if any, of assembling a telescope in space as compared to self-deployment. In this paper, we summarize the objectives of the study, a review of the status of the underlying component technologies, a description of the methodology, including three different multi-day technical interchange meetings (TIMs), summary of findings from the TIMs and other related activities. In addition, a detailed description of the various factors that impact in-space assembly, their interplay and criteria for discerning among them, a preliminary description of the life cycle plan, including the test and integration plan, and initial observations on cost and risk implications will be included in the paper.
    Keywords: Astrophysics
    Type: GSFC-E-DAA-TN58571 , International Conference for Aerospace Experts, Academics, Military Personnel, and Industry Leaders; Mar 02, 2019 - Mar 09, 2019; Big Sky, MT; United States
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  • 96
    Publication Date: 2019-07-26
    Description: This release note discusses the science data products produced by the Science Processing Operations Center at Ames Research Center from Sector 12 observations made with the TESS spacecraft and cameras as a means to document instrument performance and data characteristics.
    Keywords: Astrophysics
    Type: NASA/TM-2019-220297 , ARC-E-DAA-TN71061
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  • 97
    Publication Date: 2019-07-20
    Description: The work presented here sought to explore a portion of the parameter space of a hybrid nuclear fuel in regards to ignition and burn by analyzing the effect of initial geometry and thermodynamic conditions. The authors performed 0D power balance and 1D burn wave calculations to determine temperature progression and energy production for defined initial conditions. Geometries examined are representative of concept fuels for a Pulsed Fission-Fusion (PuFF) engine. This work focuses on lithium deuteride and uranium 235 for the fuel since these are seen as leading candidates for PuFF. Presented below is a power balance illustrating a reduction in the energy and density required to breakeven of hybrid fuels in comparison with fusion fuels. Also the impact of fusion and fissile fuel quantities upon initial energies is presented. One can see that the initial energy required to breakeven in a hybrid cylindrical nuclear fuel decreases with decreasing fissile liner thickness, decreasing fusion fuel core radius, and increasing compression ratio of the fusion fuel.
    Keywords: Spacecraft Propulsion and Power
    Type: M18-7082 , Nuclear and Emerging Technologies for Space 2019; Feb 25, 2019 - Feb 28, 2019; Richland, WA; United States
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  • 98
    Publication Date: 2019-07-20
    Description: A scale model of a NASA representative space vehicle is used to develop a refined estimate of the transient pressure loads that are expected to form at the base of the vehicle in the event of a vapor cloud explosion. Flammable vapor clouds are known to form prior to engine startup due to the significant amount of unburned hydrogen that is ejected from the combustion chamber. In the event of a vapor cloud explosion, the vehicle and payload must be able to withstand the resulting overpressure waves. The study comprises an array of pressure sensors located along the base heat shield of the scale model space vehicle as well as the interior wall and throat plug plane of the solid rocket booster. A spark source generator is used to simulate the overpressure wave produced by a vapor cloud explosion while measurements are acquired with and without the effect of a mobile launcher. Time- resolved schlieren images of the simulated vapor cloud explosion reveal the path and impact of both the initial wave and several reflected waves on the various components at the base of the space vehicle. In some instances, the reflected waves superpose to create waves that are higher in amplitude than the initial overpressure wave. A time frequency analysis of the pressure waveforms measured inside the solid rocket booster reveal a ring down tone corresponding to a standing wave that is four times the length of the nozzle.
    Keywords: Spacecraft Propulsion and Power
    Type: M19-7404 , AIAA/CEAS Aeroacoustics Conference; May 20, 2019 - May 23, 2019; Delft; Netherlands
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  • 99
    Publication Date: 2019-07-20
    Description: Jupiters moon Europa is believed to have a global liquid-water ocean beneath its icy surface. As such, it is a highly interesting destination for explorers seeking signs of life outside of Earth. This interest has given rise to the Europa Lander Mission [Hand, et al., 2017]. The central goal of the Europa Lander Mission is to place a stationary lander on Europa and make surface and sub-surface measurements, dramatically improving understanding of this Jovian moon, and potentially detecting signs of life.Placing a lander on Europa will require multiple spacecraft elements deployed across a multi-year mission timeline. Some of the key elements include: a large payload capacity rocket, such as the Space Launch System (SLS), capable of providing direct Jupiter orbit insertion; a solar-powered carrier; a de-orbit system; a sky crane landing system; and, of course, the surface lander. A noteworthy fact is that the current design requires a large solid rocket motor to provide the necessary braking thrust for the de-orbit stage. While solid rocket motors have been used extensively by NASA during launch, in-space use has been limited. In addition to the normal challenges associated with a long-distance planetary mission, the Europa Lander Mission must also contend with the high-radiation environment associated with the Jovian system. The size of Jupiter, combined with its magnetic field strength, and rotation speed, result in a harsh radiation environment composed of high energy charged particles (ions and electrons) as well as high-temperature plasmas [de Soria-Santacruz Pich, 2016]. Due to this high-radiation environment, each component of the Europa Lander spacecraft must be evaluated to determine its radiation dose tolerance and its likelihood for experiencing electrostatic charging (and discharging). In general, metal components in a Jovian environment do not pose a concern for radiation degradation; in fact, metal structures and closeouts can act as radiation shielding for the more sensitive components. Charging of a metal component is only an issue if the component is not properly grounded to the spacecraft chassis. However, electrically insulating materials, such as polymers, are subject to radiation degradation as well as surface and internal charging, and therefore require extra scrutiny. The focus of this paper will be on the insulating materials that are commonly used inside solid rocket motors. The special application of a solid rocket motor used in space after a relatively long duration flight, combined with the high energy electron environment in the Jovian system, raises concerns about the possibility of significant charging and discharging leading to reduced performance.
    Keywords: Spacecraft Propulsion and Power
    Type: M19-7372 , Applied Space Environments Conference (ASEC); May 13, 2019 - May 17, 2019; Los Angeles. CA; United States
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  • 100
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    In:  CASI
    Publication Date: 2019-07-20
    Description: No abstract available
    Keywords: Astrophysics
    Type: MSFC-E-DAA-TN66387 , Joint Astronomy Colliquium; Mar 15, 2019; Garching; Germany
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